SB20260916116 - Use-after-free in Linux kernel ceph
Published: September 16, 2026
Security Bulletin ID
SB20260916116
CSH Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-89990)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to use-after-free in ceph_mds_check_access() when a concurrent MDS session reopen occurs while access is being checked. A remote attacker can trigger concurrent access checking and MDS session reopening to execute arbitrary code.
Remediation
Install update from vendor's website.